import _testcapi
import os
import tracemalloc

FD_DOMAIN = 1
# size parameter for tracemalloc_track()
FD_SIZE = 1

_os_open = os.open
_os_close = os.close

def open(*args, **kw):
    fd = _os_open(*args, **kw); _testcapi.tracemalloc_track(FD_DOMAIN, fd, FD_SIZE)
    return fd

def close(fd):
    _os_close(fd)
    _testcapi.tracemalloc_untrack(FD_DOMAIN, fd)

def monkey_patch():
    os.open = open
    os.close = close

def main():
    monkey_patch()

    tracemalloc.start(10)

    fd = os.open(__file__, os.O_RDONLY)

    tb = _testcapi.tracemalloc_get_traceback(FD_DOMAIN, fd)
    tb = tracemalloc.Traceback(tb)

    print("fd %s was created at:" % fd)
    for line in tb.format():
        print(line)

    os.close(fd)
    assert _testcapi.tracemalloc_get_traceback(FD_DOMAIN, fd) is None


if __name__ == "__main__":
    main()